Telecommunications companies strive to keep their underground cables in good working order. One of the biggest threats to underground telephone cables is moisture. The conductors in the cables are insulated, usually with a pulp insulation or plastic.
The integrity of the protective cable sheath is compromised when cracks develop. Cracks allow water to enter and electrolysis to occur, which can result in faulted conductor pairs. The characteristics of the cable can change. For example, the noise on the line may increase or there may be cable failure.
With underground cable, the cable is susceptible to water damage due to groundwater or storm water. If there is a crack in the cable, water will permeate and cause conductor damage unless there is a positive pressure within the cable that exceeds and counters the force of the water.
Telephone companies have utilized air pressure systems to put air into their cables. When a crack develops in the cable, the air pressure inside the cable prevents water or moisture from entering the cable. Air pressure systems may include compressors and dryers, with compressors supplying the air and the dryers removing the residual moisture. Air pipes follow the cable route and introduce pressure at various fixed points along the cable route. The air pipes are connected to manifolds, which distribute air to the cables.
With these air pressure systems, telephone companies want to insure adequate air pressure throughout the system and want to detect leaks in the system. Thus, it is very important to measure the air delivery pressure at various locations within the air pressure system.
Air pressure monitoring units, such as Sparton air pressure monitoring systems commercially available from Sparton Technology, Inc., are available to take air pressure readings. In the past, the air pressure readings from monitoring units have been accessible by computers utilizing dial-up modems. However, accessing the monitoring units using dial-up modems has proven slow and forced reliance on outmoded printers and network technology. For example, the maximum connection speed in some cases has been 2400 bytes per second (bps). Due to the slow connection, the monitoring systems have typically only been polled once a day to obtain status reports.
In the past, technicians would print a status report on paper in the morning before going into the field for the day. If the technicians were in the field and needed an updated status report, they would sometimes leave a work site to return to their office and print out a paper report. In some instances, the technicians may have called someone in the office to print and read the report to them.
For example, a technician may be in the field performing work on a piece of equipment connected to the air pressure system. Examples of equipment that technician might repair in the field include an air pipe, a compressor, a manifold, a transducer, a cable splice closure, air tubes, carrier cases feeding out of cable, transducer housings, fittings for air pipes and air tubes, load coils, check valves, pressure plugs (external and internal), pressure valves, flanges placed on cables, cutoff valves, underground terminals, pressure regulators, or the cable itself. If the technician is adjusting the equipment, the technician may need “real time” pressure readings on the equipment. Under current systems, the technician must call someone in an office or technical center to obtain the data. The office receives real time pressure data from the monitoring unit. A person in the office then reads the real time pressure data to the technician in the field. Thus, under current systems, two people are required to adjust the equipment.